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Test Item Influences and Dependencies. G. Donald Allen Department of Mathematics Texas A&M University. Given and n item test. We can arrange the items in any order we wish. Problem. What is the best strategy for arranging problems on a test?
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Test Item Influences and Dependencies G. Donald Allen Department of Mathematics Texas A&M University Test Item Influences and Dependencies
Given and n item test • We can arrange the items in any order we wish. • Problem. What is the best strategy for arranging problems on a test? • Placing the easy items first followed by the more difficult ones? • Randomly placing items? • Cluster difficult and easy items separately? Test Item Influences and Dependencies
The Situation • Additional assumptions are needed, the foremost being some model of the effect of one question upon succeeding ones. • For example, if the test begins with a very difficult item, one which most students will not solve, will this event affect their state of mind, or confidence, toward solving subsequent problems? Test Item Influences and Dependencies
Goal • What we intend to show is that if we do allow test item dependencies, there can results a substantial variation on test scores depending on the ordering of the test item. Test Item Influences and Dependencies
Toward a model Test Item Influences and Dependencies
This means… Test Item Influences and Dependencies
The grade Test Item Influences and Dependencies
Influence and DependenciesHypotheses Test Item Influences and Dependencies
Parameters of Influence Test Item Influences and Dependencies
The Threshold Test Item Influences and Dependencies
Positive or Negative? Test Item Influences and Dependencies
The factors Test Item Influences and Dependencies
Boost & Fade Test Item Influences and Dependencies
Conditional Probabilities Test Item Influences and Dependencies
Psychological factors • In fact α and β are psychological factors of emotional responses to test questions. • For poor test takers α may be larger than β, and vice-versa for good test takers. • Using different α and β here makes the problem very difficult. Test Item Influences and Dependencies
Rewriting the model Test Item Influences and Dependencies
Conditional probability Test Item Influences and Dependencies
The Two Question Test Test Item Influences and Dependencies
Two Cases Test Item Influences and Dependencies
What to compare? Quantities are not comparable as is, without more information Test Item Influences and Dependencies
More Assumptions Test Item Influences and Dependencies
Easy precedes Difficult Test Item Influences and Dependencies
Many Question Test • Multiple Questions • Multiple difficulties • Constant β’s • Constant γ’s Test Item Influences and Dependencies
Many Question Test • Two possible models • Simplistic. Question i influences Question i+1 only • More realistic. The influence for question i+1 comes from all preceding questions, though perhaps with fading memory. Test Item Influences and Dependencies
Simple Model Grade Test Item Influences and Dependencies
Optimize Test Item Influences and Dependencies
Strategies and Observations Test Item Influences and Dependencies
Expanded version Test Item Influences and Dependencies
An Interesting Connection Traveling Salesman problem Test Item Influences and Dependencies
Traveling Salesman Test Item Influences and Dependencies
The Two Difficulties Test Test Item Influences and Dependencies
Main Result Test Item Influences and Dependencies
Proof (sketch) Test Item Influences and Dependencies
Step two. Test Item Influences and Dependencies
Step Three Test Item Influences and Dependencies
Avoiding every single detail, we have… Test Item Influences and Dependencies
Multiple Item Difficulties • Here there are no clear answers. • It seems somewhat dependent on gamma, unless • Essentially, we can demonstrate there is no universal algorithm for a priori arranging the test items. Test Item Influences and Dependencies
Ordering the Other Test Items Test Item Influences and Dependencies
Local Strategy Test Item Influences and Dependencies
A Weaker Local Result Test Item Influences and Dependencies
Case 1 Test Item Influences and Dependencies
Case 2 Test Item Influences and Dependencies
Case 3 Test Item Influences and Dependencies
Comments Test Item Influences and Dependencies